Identifying top partners at LHC

TL;DR

This paper explores how to detect and identify new vector-like quarks at the LHC by analyzing various final states and decay channels, demonstrating the potential for discovery with specific luminosity thresholds.

Contribution

It provides a systematic analysis of signals for vector-like quarks at LHC, including multiple decay channels and final states, to improve detection strategies.

Findings

Single lepton channel offers the best discovery potential.

Discovery luminosities range from 0.16 to 1.9 fb^-1 for 500 GeV quarks.

Different quark representations affect detection thresholds.

Abstract

We systematically study the possible signals at LHC of new vector-like quarks mainly coupled to the third generation. We consider heavy quarks T, B, X, Y of charges 2/3, -1/3, 5/3 and -4/3, respectively, in SU(2)_L isosinglets T_{L,R}, B_{L,R}, or isodoublets (T B)_{L,R}, (X T)_{L,R} or (B Y)_{L,R}. Analyses based on a fast detector simulation are presented for twelve different final states containing one, two, three or four charged leptons in several invariant mass regions, also considering various b quark multiplicities. It is shown that with the combination of the different channels the new quarks can be identified and their charged and neutral decays established. The comparison among final states also shows that the single lepton one offers the best discovery potential at LHC. For heavy quark masses of 500 GeV, the 5 sigma discovery luminosities range from 0.16 fb^-1 for a (X T)_{L,R} doublet to 1.9 fb^-1 for a B_{L,R} singlet.